Method of passing cooling medium through a tuyere



Oct. 8, 1968 w. E. SLAGLEY 0 METHOD OF PASSING COOLING MEDIUM THROUGH ATUYERE Original Filed June 25, 1965 2 h ts-She t l ai 1& IN-70R man ATTOR/VEYS Oct. 8, 1968 w. E. SLAGLEY 3,404,662

METHOD OF PASSING COOLING MEDIUM THROUGH A TUYERE Y Original Filed June25, 1965 2 Sheets-Sheet 2 IN VE N TOR United States Patent 3,404,662METHOD OF PASSING COOLING MEDIUM THROUGH A TUYERE William E. Slagley,Crown Point, Ind., assignor to Inland Steel Company, Chicago, Ill., acorporation of Delaware Original application June 25, 1965, Ser. No.467,031, now

Patent No. 3,351,335, dated Nov. 7, 1967. Divided and this applicationAug. 30, 1967, Ser. No. 664,400

2 Claims. (Cl. 122-6.6)

ABSTRACT OF THE DISCLOSURE A tuyere having a cooling medium passagetherein which includes a first convolute-shaped section, an inletsection connected to the convolute-shaped section, a third section whichhas one end terminating with the outlet end of the convolute sectionwhile the remaining end of the third section terminates as an end of anoutlet section. Cooling medium is circulated through the cooling passageat a uniform velocity in the range of about feet to about 11 feetwhereby the cooling medium moves progressively from head end to the noseend and subsequently back to the head end without overlapping itself.

This is a divisional of William E. Slagley application Ser. No. 467,031,filed June 25, 1965, now Patent No. 3,351,335.

The present invention relates generally to an improvement in air blastnozzles and more particularly relates to tuyeres employed in blastfurnaces.

In blast furnace operations, circulating water cooling systems areemployed in tuyeres in order that the heat transferred from the blastfurnace to the tuyeres is carried away by the circulating water tominimize heat buildup in the tuyeres.

In a number of tuyeres presently available, the cooling water system isineflicient in heat removal such that hot spots build up on the tuyerewhich eventually cause a tuyere rupture thereby allowing the coolingwater to enter into the furnace or permitting furnace gases to force thecooling water backwards in the cooling system. Cooling water systems inother tuyere arrangements suffer from the fact that to achieve anincreased water rate at a particular location in the tuyere, the area ofthe cooling water passage at that point is so reduced that a distinctdanger of plugging the water passage is inherent in these units.

Other tuyere arrangements, while perhaps achieving the desired rate offiow for the cooling medium, are either too bulky in construction orhave a tuyere contour which requires special handling in order toproperly install and position the tuyere within the furnace. This isquite unsatisfactory, particularly when in the course of proper furnacemaintenance or some emergency, one or more of the furnace tuyeres mustbe replaced in which instance it is necessary to complete the withdrawalof the old tuyeres and installation of the new tuyeres in as short atime as possible.

In order to obviate these and other disadvantages, I have invented a newand novel tuyere having a cooling system which increases the tuyerecooling efficiency by circulatin'g the fiow of water conventionallyutilized, at a substantially higher velocity.

The increased velocity achieved with my tuyere is achieved by passingthe cooling medium through a convolute-shaped water passage. The tuyere,generally made of copper, is maintained cold enough so that atsubstantially all times during operation of the blast furnace it iscovered with slag and thus protected, Moreover, the cooling rate of myimproved tuyere is sufficiently high that even contact with molten ironwill not burn the tuyere.

3,404,662 Patented Oct. 8, 1968 The velocity of the cooling water tuyereis uniform throughout the cooling system such that restrictions, whichare required in some tuyeres available today, are eliminated therebyobviating the possibility of plugging up the cooling medium passage.

Also, because the arrangement of my cooling system is in one cylindricalplane so that the tuyere shape is symmetrical about its center line, theneed for the inlet or outlet passage to cross over other cooling waterpassages thereby causing a hump in the tuyere or a special tuyerecontour is eliminated. Further, because of the increased coolingefficiency accomplished with my tuyere, tuyere life is substantiallyextended so that maintenance costs incurred for replacing conventionaltuyeres is reduced.

In my new and improved tuyere, a convolute-shaped cooling passageprovides the flow path for cooling water travelling at a high, uniformvelocity whereby the cooling medium travels in a substantially helicalmovement as it moves along the length of the tuyere.

In the drawings:

FIGURE 1 shows a fragmentary view of my tuyere positioned within a wallof a furnace;

FIGURE 2 shows a sectional view along line 22 in FIGURE 4;

FIGURE 3 shows a perspective view of the cooling water passagepositioned within the outline of the tuyere;

FIGURE 4 shows an end view of my tuyere; and

FIGURE 5 shows a sectional view taken along line 55 in FIGURE 2.

In the drawings and more particularly FIGURE 2, there is shown tuyere 10having a nose end 11, which extends into the furnace, and a head end 12,the tuyere hav ing central opening 13 throughout its length. Blow pipe 9engages with tuyere 10, the blow pipe fitting against recess 8, FIGURE2, of head end 12. Head end 12 is tapered to fit against a complementarytapered portion of tuyere cooler 7. Disposed between the inner wall 14and outer tapered Wall 15 is a cooling medium passage 17 through which asuitable cooling medium, e.g., water, is circulated for heat transferpurposes.

Passage 17, as more clearly shown in FIGURE 3, is comprised of a firstconvolute-shaped section 18, a second inlet section 21, a third section19 and a fourth outlet section 20. Convolute section 18 comprises aplurality of convolutions which, when bent into the cylindrical shapeshown in FIGURE 3, provide a cooling water passage for substantially theentire length of tuyere 10. When the individual convolutes 22 are bentto form the cylindrical shape, the edges 24, 25 of the convolutes, whichnormally would be in an abutting position if a complete cylinder wereformed, are spaced apart for reasons to be described hereinafter.

Section 19 which has one end integral with convolute section 18 is asubstantially straight tubular section whose remaining end terminates asan end of outlet section 20. The remaining end of outlet section 20 iscircular in shape and tapped to receive a threaded conduit means, notshown. Similarly, section 21 has one end which terminates into an end ofconvolute section 18 while the remaining end of inlet section 21 iscircular in shape and tapped to receive a threaded water conduit, notshown, the inlet and outlet conduits serving to transport acoolingmedium throughout passage 17.

Section 19 which extends for a major portion of the length of thecooling water passage is located in close proximity to edge 25 ofconvolute section 18 as seen in FIGURE 3, while the remaining edge 24 ofsection 18 is spaced substantially away from section 19, If desired,this space could be eliminated and edges 24, 25 of convolute section 18could be located contiguous to each other. However, in some instances,it is desirable to have an 3 7 additional gas conduit passage, notshOWn, and I have provided room for such occurrence whereby an openingcould be made in the tuyere wall-without-interfering with cooling mediumpassage 17.

The velocity of the cooling medium is substantially uniform throughout"the entire passage 17, the size of the opening in passage 17 being thesame throughout the system.

The size of the opening throughout passage 17 is substantially uniformso that no clogging or plugging occurs as is the case with some tuyereswhich require restrictions in the cooling medium passages in order toachieve maxi mum cooling medium velocity at the nose portion of thetuyere. With my design, I achieve an increased water velocity overtuyeres presently available while utilizing the same anticipated flow ofcooling medium which normally is about 43 gallons of water per minute(g.p.m.). The cooling water is directed through cooling passage 17having a passage area of about 1.25 square inches at a velocity of about11 ft./sec. as opposed to present designs wherein water velocity ismaintained at about 0.41 ft./ sec. and special restricting means arerequired to increase the-velocity at the nose of the tuyere. It is theincreased water velocity with the water flow remaining the same aspresently utilized that accomplishes the high heat transfer rate andkeeps my tuyere cooler than tuyeres presently available. Moreover, thecooling medium path is directed to essendaily the entire surface of thetuyere which serves to minimize the presence of local hot spots.

For satisfactory results, I desire to design passage 17 whereby it willprovide a minimum water velocity of about ft./sec. with a preferablevelocity of about ft./sec. based on a cooling water flow between 40-45g.p.m.

'As seen in FIGURE 2, passage 17 is preferably elliptical-shapedthroughout its length save at its inlet and outlet ends where it iscircular to receive standard conduit means. A specific embodiment of mynovel tuyere has a length of 15 inches with a gas opening 13 of about 7inches diameter. The cross-section of passage 17 as exemplified at thelocation shown in FIGURE 2 has an overall passage width of about 1%inches with R equalling "A6 inch.

The tuyere is preferably copper cast having the cooling water passageplaced therein by means of a shell core. However, if desired, one couldinitially form a copper tubing to have a cooling medium passagecomprising the into the tuyere,

convolute section; substantially straight section and outlet and inletsections after which the remaining portion of the'tuyere could be castaround the formed tubing.

In addition to tapping inlet and outlet opening in the passage forreceipt of conventional cooling water pipes, a third hole 30 is tappedinto the tuyere. In removing the tuyere from its position in the blastfurnace, a rod is screwed into tapped hole 30 and the tuyere can bepulled from the furnace wall.

Insulation'31 which lines opening 13 for a substantial portion of itslength is employed to prevent heat loss from hot gas being blasted intothe furnace, the insulation being generally /2 inch thick high aluminumcastable refractory insulation or other suitable material.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limi- -tation's should beunderstood therefrom, as modifications will be obvious to those skilledin the art.

What is'claimed is:

1. The method of passing a cooling medium through a tuyere having anouter wall, a nose end, a head end and an inner wall forming a centralopening along the longitudinal axis of said tuyere according to thesteps of:

passing a cooling medium at a uniform velocity in the range of about 5feet to about 11 feet per second throughout a cooling medium passagethrough said tuyere by:

directing said medium to flow progressively about the longitudinal axisof said tuyere in a direction from said head end of said tuyere towardsaid nose end of said tuyere; and

subsequently directing said medium backto said head end of said tuyerewhereby said medium is free of overlapping itself as it is directedthroughout said -tuyere.

2. The method of passing a cooling medium through a tuyere in accordancewith the steps of claim 1 wherein said cooling medium is passed at avelocity of about 11 ft./sec.

References Cited UNITED STATES PATENTS 265,156 9/1882 Sheets 1226.62,823,522 2/1958 Collins l69 XR 3,280,903 10/ 1966 Stoddard 165-469 XRKENNETH W. SPRAGUE, Primary Examiner.

